I'm slightly confused. What exactly are you trying to do? If all you want to do is use an existing texture you shouldn't be going into logging mode. Logging mode + package build are for extracting textures and creating .tpf files.
If you're having trouble getting Texmod to run with GW, try running it (GW) without Texmod. Usually if there are updates Texmod won't apply.
Other than that, I'm using the 'Cartography Made Easy Complete Collection' instead of individual ones, which gives me a nice clear blue overlay instead of that horrible brown one. Perhaps try that.
Don't know anything about this either.